Oblique impact on ceramic–composite armor system: A numerical study

Abstract

In this investigation, simulations are conducted to assess the ballistic resistance of an armor system composed of 95% alumina–Kevlar 29/epoxy composite subjected to normal and oblique impact. The oblique angles are varied from 0° to 70° in the step of 10-degree increments, and the projectile's impact velocities range between 220 and 1200 m/s. The present simulation results are aligned with existing numerical and experimental data available in the literature, demonstrating the consistency and reliability of the approach. Special attention is provided to obtain the critical oblique angle at which the projectile's penetration mode switches from perforation to embedment or ricochet. The simulation results also include the projectile's residual velocities, ballistic limit velocities, and the armor system's performance in terms of penetration or damage for normal and oblique impact. It is established that the oblique angle of the projectile significantly alters the effectiveness of the ceramic–composite armor against ballistic impact. When dealing with oblique angles below 30° (< 30°), the reduction in the projectile's residual velocity, as the obliquity angle increases, is limited to a maximum of 15%. This implies that the target's perforation resistance exhibits less sensitivity to the applied load of the projectile in this range. However, when incident angles exceed 45° (> 45°), the ballistic limit velocity has a significant and abrupt rise due to the augmented effective target thickness under oblique impact conditions.